void setup() {
  // put your setup code here, to run once:
  for(int i = 2; i < 4; i++){
    pinMode(i,OUTPUT); 
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i = 2; i < 4; i++){
    digitalWrite(i,HIGH);
    delay(2000);
    digitalWrite(i,LOW);
    delay(3000);
  }
    for(int i = 3; i > 1; i--)
    {
      digitalWrite(i,HIGH);
      delay(3000);
    }
    digitalWrite(2,LOW);
    delay(3000);
}
